diff --git a/acipher/ta/acipher_ta.c b/acipher/ta/acipher_ta.c
new file mode 100644
index 0000000..71b918a
--- /dev/null
+++ b/acipher/ta/acipher_ta.c
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+ * Copyright (c) 2018, Linaro Limited
+ */
+
+#include <inttypes.h>
+
+#include <tee_internal_api.h>
+
+#include <acipher_ta.h>
+
+struct acipher {
+	TEE_ObjectHandle key;
+};
+
+static TEE_Result cmd_gen_key(struct acipher *state, uint32_t pt,
+			      TEE_Param params[TEE_NUM_PARAMS])
+{
+	TEE_Result res;
+	uint32_t key_size;
+	TEE_ObjectHandle key;
+	const uint32_t key_type = TEE_TYPE_RSA_KEYPAIR;
+	const uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_VALUE_INPUT,
+						TEE_PARAM_TYPE_NONE,
+						TEE_PARAM_TYPE_NONE,
+						TEE_PARAM_TYPE_NONE);
+
+	if (pt != exp_pt)
+		return TEE_ERROR_BAD_PARAMETERS;
+
+	key_size = params[0].value.a;
+
+	res = TEE_AllocateTransientObject(key_type, key_size, &key);
+	if (res) {
+		EMSG("TEE_AllocateTransientObject(%#" PRIx32 ", %" PRId32 "): %#" PRIx32, key_type, key_size, res);
+		return res;
+	}
+
+	res = TEE_GenerateKey(key, key_size, NULL, 0);
+	if (res) {
+		EMSG("TEE_GenerateKey(%" PRId32 "): %#" PRIx32,
+		     key_size, res);
+		TEE_FreeTransientObject(key);
+		return res;
+	}
+
+	TEE_FreeTransientObject(state->key);
+	state->key = key;
+	return TEE_SUCCESS;
+}
+
+static TEE_Result cmd_enc(struct acipher *state, uint32_t pt,
+			  TEE_Param params[TEE_NUM_PARAMS])
+{
+	TEE_Result res;
+	const void *inbuf;
+	uint32_t inbuf_len;
+	void *outbuf;
+	uint32_t outbuf_len;
+	TEE_OperationHandle op;
+	TEE_ObjectInfo key_info;
+	const uint32_t alg = TEE_ALG_RSAES_PKCS1_V1_5;
+	const uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_MEMREF_INPUT,
+						TEE_PARAM_TYPE_MEMREF_OUTPUT,
+						TEE_PARAM_TYPE_NONE,
+						TEE_PARAM_TYPE_NONE);
+
+	if (pt != exp_pt)
+		return TEE_ERROR_BAD_PARAMETERS;
+	if (!state->key)
+		return TEE_ERROR_BAD_STATE;
+
+	res = TEE_GetObjectInfo1(state->key, &key_info);
+	if (res) {
+		EMSG("TEE_GetObjectInfo1: %#" PRIx32, res);
+		return res;
+	}
+
+	inbuf = params[0].memref.buffer;
+	inbuf_len = params[0].memref.size;
+	outbuf = params[1].memref.buffer;
+	outbuf_len = params[1].memref.size;
+
+	res = TEE_AllocateOperation(&op, alg, TEE_MODE_ENCRYPT,
+				    key_info.keySize);
+	if (res) {
+		EMSG("TEE_AllocateOperation(TEE_MODE_ENCRYPT, %#" PRIx32 ", %" PRId32 "): %#" PRIx32, alg, key_info.keySize, res);
+		return res;
+	}
+
+	res = TEE_SetOperationKey(op, state->key);
+	if (res) {
+		EMSG("TEE_SetOperationKey: %#" PRIx32, res);
+		goto out;
+	}
+
+	res = TEE_AsymmetricEncrypt(op, NULL, 0, inbuf, inbuf_len, outbuf,
+				    &outbuf_len);
+	if (res) {
+		EMSG("TEE_AsymmetricEncrypt(%" PRId32 ", %" PRId32 "): %#" PRIx32, inbuf_len, params[1].memref.size, res);
+	}
+	params[1].memref.size = outbuf_len;
+
+out:
+	TEE_FreeOperation(op);
+	return res;
+
+}
+
+TEE_Result TA_CreateEntryPoint(void)
+{
+	/* Nothing to do */
+	return TEE_SUCCESS;
+}
+
+void TA_DestroyEntryPoint(void)
+{
+	/* Nothing to do */
+}
+
+TEE_Result TA_OpenSessionEntryPoint(uint32_t __unused param_types,
+					TEE_Param __unused params[4],
+					void **session)
+{
+	struct acipher *state;
+
+	/*
+	 * Allocate and init state for the session.
+	 */
+	state = TEE_Malloc(sizeof(*state), 0);
+	if (!state)
+		return TEE_ERROR_OUT_OF_MEMORY;
+
+	state->key = TEE_HANDLE_NULL;
+
+	*session = state;
+
+	return TEE_SUCCESS;
+}
+
+void TA_CloseSessionEntryPoint(void *session)
+{
+	struct acipher *state = session;
+
+	TEE_FreeTransientObject(state->key);
+	TEE_Free(state);
+}
+
+TEE_Result TA_InvokeCommandEntryPoint(void *session, uint32_t cmd,
+				      uint32_t param_types,
+				      TEE_Param params[TEE_NUM_PARAMS])
+{
+	switch (cmd) {
+	case TA_ACIPHER_CMD_GEN_KEY:
+		return cmd_gen_key(session, param_types, params);
+	case TA_ACIPHER_CMD_ENCRYPT:
+		return cmd_enc(session, param_types, params);
+	default:
+		EMSG("Command ID %#" PRIx32 " is not supported", cmd);
+		return TEE_ERROR_NOT_SUPPORTED;
+	}
+}